Since I’m the original skeptic of the unemployment rate — a skepticism that goes back decades — I’m happy to see journalists like Leonhardt (and, more important, his paper) finally come over to the side of truth and justice.

So there now seems to be a concerted effort at the Times to answer the puzzling question: if the jobless rate is really falling, why are Americans still so glum?

I don’t want to go back to square one on this issue but a quick explanation of the basics is necessary.

A long, long time ago I explained that the jobless rate was a terrible measure on which to base any policy.

The so-called U-2 jobless rate that you see in the headlines on the first Friday of every month declines when people become so discouraged that they stop looking for work. The opposite is also true: the jobless rate goes up when folks are becoming optimistic and begin again to look for jobs.

That’s just the way it works.

So this is a perverse indicator. And on that basis alone the unemployment rate should be trashed by policy-makers and anyone trying to seriously analyze the labor markets.

“Americans are less willing to respond to surveys than they used to be,” Leonhardt wrote, adding, “A new academic paper suggests that the unemployment rate appears to have become less accurate over the last two decades, in part because of this rise in non-response.”

There are so many things wrong with Leonhardt’s analysis that I don’t know where to start.

But the first thing you should know is that the report he is quoting was co-written by Alan Krueger, now a Princeton economist and formerly chairman of President Obama’s Council of Economic Advisers.

Since he’s relying on a prominent Democrat, Leonhardt probably should also have mentioned that the jobless report started to be perverted during the Bill Clinton administration.

Lots of people who would have been considered jobless back in 1994 lost that status because of Labor Department re-definitions under Clinton.

To be fair, the Republicans did nothing to put the unemployment rate back on the old standard when President Bush took over.

I guess all politicians like to make people think the job market is improving, even if it’s not.

But that’s not my biggest gripe with Leonhardt and Krueger.

This is: If Americans are no longer as willing to answer questions from the government, how has the Census Bureau (which conducts the jobless survey for Labor) kept its response rate near the required 90 percent?

If people are balking at surveys (and I don’t doubt they are), shouldn’t the response rate on the jobless survey have fallen dramatically?

The fact is, the only way to keep the response rate as high as it is — if what Leonhardt and Krueger report is true about the lack of cooperation — is to cheat.

Leonhardt and Krueger are way behind the curve on this one.

Over the last year Census has had trouble hitting the 90 percent jobless survey response rate demanded by Labor.

It is true that more people refused to take the survey. But it is also true that some Census workers cheated and filled out the surveys themselves — or, perhaps, their supervisors did.

This cheating allowed Census to maintain its 90 percent success rate — until I wrote about it and it was forced to stop. Now they are having trouble hitting that high completion rate.

At least two House probes into the cheating are now under way.

Leonhardt and Krueger would like you to believe that the underpaid enumerators at Census, who work in the field without any close supervision, are that good at charming people into answering personal questions when surveyors for private polls are having a heck of a time getting responses.

Really, what are the chances of that?

The practice of manipulating data is legendary at Census. In fact, internally it even has a name: curb-stoning.

This is the practice of enumerators sitting on a street curb and filling out forms themselves, rather than walking up to someone’s door and conducting an interview.

The Times columnist started his piece by saying the “Labor Department’s monthly jobs report has been the subject of some wacky conspiracy theories.” That’s such a easy explanation for a lazy journalist.

The fact is that over the last year Labor’s jobs report — because of revelations from this space — has been the subject of a full-blown probe by the US Department of Commerce Office of the Inspector General, which has recommended significant changes in the data-gathering process.

Those changes are now being implemented.

Congress will undoubtedly look into the 120 Census laptops that happened to go missing in the weeks leading up to the last presidential election.

Those laptops contained data that could have been used to fudge the jobless rate.

Where’d the information about the missing computers come from? No, not from some crazy conspiracy blog. That information came directly from Census e-mails that The Post had to work hard to get.

And I am striving to get more e-mails that’ll shine an even brighter light on what is going on.